i got a 5.9 V8 with almost 140,000 miles. the coolant level drops rapidly enough that my heads up display beeps at me at about every 10 to 14 days that my coolant is low. I dont know what is wrong, there are no easily visible signs of a leak like coolant on my garage floor.
i have had only one over heating warning and that was when i was REALY getting on the gas cuz i was doing donuts. other wise my temp stays around the mid at 210.

help me!!! even a diagnosis would help, if i can get an idea to what it is my friends will be able to fix it.

PLZ HELP!!!

Last edited by 5.9 andy on Mon Mar 05, 2007 6:26 pm; edited 1 time in total

Everytime I've seen this happen there has been a leak somewhere. I have to assume the Grand's have a heater core and it's leaking there, or leaking on a hose somewhere when the vehicle is running. Anybody else?

It could very well be leaking while it's running. It could be burning it too. Take a sample of the coolant, and test it for the presense of exhaust gases. The test tells you if coolant is getting into the combustion chamber which would indicate a bad head gasket, bad head, etc. I've mentioned this test here before. You can get a test kit from Napa, or buy it online. Most good parts stores will have it. Some places will test the coolant for you. See link.

23: External coolant leakage
--------------------------------
1. Deteriorated or damaged hoses or loose clamps. Replace hoses and/or tighten the clamps at the hose connections.
2. Water pump seals defective. If this is the case, water will drip from the weep hole in the water pump body.
3. Leakage from the radiator core or side tank(s). This will require the radiator to be professionally repaired.
4. Engine drain plug leaking or water jacket core plugs leaking.

Hope this helps. I'm not a mechanic but you can certainly follow these guidelines provided by the manual troubleshooting and it may help you pinpoint exact problems. Do treat this serious problem before it gets out of hand and kills the engine.

If the pressure check fails its going to be the problems mentioned above, hole in radiator, cap is bad, cracked head, head gasket,

since you said it got hot my guess is head gasket

does it have problems starting or idling when its cold? Does it smell like its burning antifreeze from the tail pipe?_________________96 Cherokee 7.5 inch TnT long arm Locked F/R, D44 rear, 4.56s, 35x12.50 Muds/36x12.50 TSLs

ehh you can tell when it burns antifreeze it kinda smells like antifreeze, not to be a smartass or anything_________________96 Cherokee 7.5 inch TnT long arm Locked F/R, D44 rear, 4.56s, 35x12.50 Muds/36x12.50 TSLs

well does it look like coolant is coming outa the cap, like is there coolant splashed on top of the cap and fan shrouding if not then its probly not the cap but if you do go by NAPA or whatever part store, ask them to pressure test the cap before you buy a new one.

Burning antifreeze smells sweet, like burnt sugar and tends to make white smoke. If you were losing that much thru your head gasket, you'd have a plume of white smoke evry time you stepped on the gas, or your oil would turn milky white. Try putting a clean piece of cardboard under your truck right after you've topped off the coolant and after you've driven awhile to get the engine hot. Leave the engine idling for about 10 minutes,I BET you'll see green spots that if you taste a TINY bit of will taste sweet and will be coolant. If that doesn't work, go buy some ultraviolet dye, at NAPA auto parts store, and follow the directions. My gut tells me that your water pump is leaking, as this usually only leaks bad if the engine is running. To check your water pump, look underneath the water pump, behind the pulley, use a flashlight, theres a tiny little hole called a "weep hole" it's hard to see. Look for water tracks, the coolant will dry up really fast 'cause it's hot right there. Good Luck!!